Telephone-exchange system



Dec. 11, 1928. 1.6951049 E. JACOBSEN ET AL TELEPHONE EXCHANGE SYS TENFiled Sept. 11, 1925 3 Sheets-Sheet 1 [77 7/7 Jacofikser r. A, m WA/wm6." p y- Af/M I. I 7 H12 Fig.2

'Dec, 11, 1928. 1,695,049

E. JACOBSEN ET AL TELEPHONE EXCHANGE SYSTEM Filed Sept. 11, 1925 sSheets-Sheet 2 IIHI- 9 4 w m 9 a 6 R. 1 t m cuNEiSl s 3 M nms ww E GDsCt Bum O CNd Am JPN .EF m m ca 2 9 1 I .l 3 D 8% Patented Dec.-11,1928;

) UNITETDSTATES Al l NT OFFIC EMIL'JAGOBSEN, or roar WASHINGTON, AnnARTHUR 13.; srnnnY, OF: Nnw YoRK, i v

. N. Y.; SAIIJ J-AGOBSEN ASSIGNOR TO AMERICAN TELEPHONE TELEGRAPHCOMPANY, A GORFORKTION OFITE'W YORK, ,AND; SAID PERRY 'ASSIGNOR 'IO'WEST- nan nnncrmc eonrnnr, or NEW YORK.

e Application filed September This invention relates to telephonesystems and more particularly to circuits for automatically extendlngconnectlons to lnterce tim erators ositions.

station, each comprising oneof the talking" conductors and a groundlead. In such areas,

, when it becomes necessary to add additional equipment to care for thegrowth of the exchange, it is desirable and more economical to installequipment of a'more modern character which is designed to function overtullmetah lic circuits extending to the substationsgthereby eliminatingthe ground. return. When such modern equi nnent is added to an existtusmay function together so that all subscribers may have access to eachothers lines and to the several operatorspositions."

The object of this invention is therefore to provide an improved meansfor intercepting calls from a dial station ma two-wire office to a dialstation in athreewireofiice.

automatically operabie means in anintercepting operators cord circuit topreventoperation of call charging apparatus. 7

Fig. 1 of the drawings shows at 1t's upper left hand corner asubserlbers statlonin a two-wireofiice connected to a line switchLS anda two-wire first selector FSwhichin turn has access to arepeater R. Therepeater is extended to the three-wire oflice by the trunk designated byconductors 134 and 135 which terminate in the first trunk selectors.

Fig. 2 showson its left hand side a connector C in a three-wire otficewhichhas access to the interceptingoperators trunk IOT. An interceptingoperators cord circuit is shown atIOG on the right hand side ofthisfigure. f

1 Fig. 3 at its upperleft handcorner' shows a manual operators cordcircuit OC.- The outgoing trunk OT extending between the two-wireoffice" and the three-wire oflice is 111g exchange, it becomes'necessarytopro- INCQRPQRATED, OF llEW YORK, N. Y., ACORPORATION'rnLnrnonn-nxonanen sysr nn.

11, 1925. 'seriai'no. 55,652. 1

designatecl' by 834: and 335ywhich is inturn connected to the firstselector FTS. i e

Fig. 1 isj'a diagram showing the manner" in whichthe several figuresmay-be combined to completely disclose the invention; Y t

Of the two embodiments ofytheinventi'on. illustrated in the abovefigures the one shown in Figs. 1 and 2 is preferred. i A'cleareridea'of'the operation ofthe inven tion may be had from the followingdetailed description. r

:When subscriber 100 removes there'ceiver. from the switchhoolg-lineswitch LS operates and closes spring combination 102 in a mannerWellknown in the art. Relay 104 is a I polarized r lay and does notoperat eat this" timeg as itxis used forcontrolling the message iregister circuit and is underthecontrol of. the called party. Subscriber100 now oper-T7 ates diallOlQ Relay 109 inithe'fi'rstselectorFS"operates over a circuit from ground through the left windingotrelay109youter left back contact of relay 107,.tip of springcombination'102, dial 101, subscribers 10015,"?5'

I I winding of relay 109 Rela-y 109 fo'llowsthe A feature of theinventionis inithe provision of means'in trunk circuits respon'slveto Iand 113 to step the brushes 110, 111 and-.112

to'thcdesired group ofban'k terminalshas35 been-omitted from thedisclosure "for the sake: of'brevity. As soon as the primary move Inient of the switch is completedja circuitisf established in the usualwell-known manner for the secondary magnet 108' whichqfunc tions to stepthe brushes in search of an'idle" trunk-in the selected group. VVhen'anidle trunk is found the "stepping magnet 108' ceases to operate andrelay 107 operates and closes the tip andlring leads through toconductors "117 and 118 ofifepeater' B. When brushes 110, 111 and-112make contact with p v terminals 120, 121 and 122 "acircuit is closedfrom battery'through the winding ofrelay j" r 116 inner right back"contact 015 relay 12 913 001, 7 1

terminal 122; brush 112, right front contact of relay 107, to'gro'und onthe front contact o ff I relay 113. Relay 116, operated, locks to groundover the circuit hereinbefore traced and prepares through its innerright front contacta circuit for relay 129 which is completed later.Another circuit is closed from battery through the left winding of relay115,

inner right back contact of relay 1233, con- 7 doctor 118, terminal 121,brush 111, inner left front contact of relay 107, winding of relay 104,through the spring combination 102, subscl'ibcrs station 100, dial 101,spring combination 102, outerleft front contact of relay 107, brush 110,terminal 120, conductor 117, inner left back contact of relay 123 toground through the right winding of relay 115. The operation of relay115 closes an obvious circuit for the operation of relay 124. Relay 124at its inner right front contact also conneets groundto the holdingcircuit of relay 11 6and over terminal 122, brush 112, right frontcontact of relay 107, replacing the ground supplied by relay 113 beforerelay 1 113deener izes following the cutting throng of the ta ingconductors of switch FS. lVhcn the dial 101 at the subscribers station100 is operated relay 115 releases in response to the interruptions ofits circuit and transmits pulses over a circuit from ground on the outerright back contactof relay 123, right back contact of relay 115, leftfront contactof relay 124, conductor 134, inner left back contact ofrelay 132, through the winding of vertical relay 130 of switch S.

heoperation ofvertical relay 130 closes a circuit from groundon contact152 through the winding of vertical magnet 144 to battery on the backcontact of release magnet 1 86, thereby operating the vertical magnet acertain number of times accord in g to the digit dialed and causingbrushes 140, 141, and 142 to move upward. Upon the first release ofrelay 115 with relay 124, operated, a. circuit is closed from ground onthe left back contact ofrelay115, outer ri ht front contact of relay124, to battery tlirough the winding of relay 126. Relay 126 being slowto release j does not release upon the opening of the circnitby theoperation of relay 115 While following the dial pulses. The operation ofrelay 126 closes'acircuit for the operation of relay 127 from ground onthe outer right back contact of relay 129, inner right-front contact ofrelay 126 to battery through the Winding of rela 127. vThe operation ofrelay 127 closes an o viouscircuit for the operation of relay 128. Relay128, operated, looks over a circuit from ground over the inner rightcontactof relay 124, normal contact of relay 125 to battery through theright front contact and Winding of relay 128.

When dial 101 returns to normal, relay 115 remains operatedholding relay124 operated but the operating circuit for relay 126 is opened,allowingit to release. The release of relay 126 opens the circuit forrelay 127,

and, as relay 127 is slow to release, its contacts will still be closedafter the contacts of relay 126 are opened. Therefore, a circuit will beclosed for operating rotary relay 131 from ground on the outer rightback contact of relay 129, inner right back contact of relay 126, outerright front contact of relay 127, conductor 135, off-normal contact 199,outer back contact of relay 132 to battery through the winding of rotaryrelay 131. The operation of relay 131 closes a circuit from battery atthe contact of release magnet 136, Winding of private magnet 137 .toground on contact 153 of relay 131. The operation of magnet 137 closes acircuit from battery winding of rotary magnet 138 and winding and outerfront contact ofmagnet137 through the winding of relay 133 to groundover test brush 142. The circuit of magnet 138 is thus maintained andthe switch brushes are advanced in a hunting movement until an idletrunk is found when magnet 137 will deenergize and open the circuit ofrotary magnet 138. Relay 133, which was included in the circuit ofmagnet 137, doesnot receive sufiicient current in series with n'iagnet137 to operate at this time. A circuit is now closed from batterythrough the rotary magnet, winding of relay 132, secondary olfnormalspring combination 139, to ground on the primary off-normal springcombination 143. Relay 132 operates and closes conductors 134 and 135through to brushes 140 and 141. V

The connection has now been completed toconnector C whichhasbeen foundidle and brushes 140, 141 and 142 are resting on contacts 210, 211 g and212. closed is substantially identical with thoco n nector switch shownin the patent to'Falcs The connector dis- 1,186,563 and operates in amanner fully disclosed therein. 1 It is'of course obvious that anywell-known connector switch of the threewire type might be used in placethereof. A circuit is partially closed from battery through the middleback contact of spring combination 219, winding of vertical relay 201,terminal210, brush 140, inner front contact of relay 132, conductor 134left front contact of relay 124, to the right armature of rel ay 115.101 todial the next digit, relay will release,completing this circuitthrough its right back contactto ground at the outer right back contactof relay 123 and operating relay 201 When subscriber 100 operates dialtelephone circuit.

241 thereby connecting ringing current for operating relay 125 over acircuit described below. The operation of relay 253 closes anobviouscircuit for relay 258 and relay right front contact of relay 254 tobattery through the winding of relay 251 thereby operating it. Relay 251locks to ground on the right front contact of relay 252 over an obviouscircuit. The operation of relay 251 connects the tip side of plug 241 toconductor 263 and thence to the intercepting operators Through therelease of relays 260, 253 and 258, following the deenergization ofrelay 257, relay 254 has released and a circuit is now closed fromground on the back contact of relay 257, outer rightback contact ofrelay 254, outer right front contact of relay 251, back contact of relay250, to battery through the-winding of relay 256. Relay 256, operated,lights lamp 258.

As soon as relay 251 has operated the tip and ring conductors areextended to the bridge 250 across the operators cord circuit. Relays 216and 217 operate in series with this bridgeand the relay 209 is thusprevented from reoperating.

The operator may insert the plug 241 during a ringing interval, namely,during the time the relay 209 is operated. In this case the relay 257 isoperated in a circuit from the grounded generator 214 to the left frontcontact of relay 209, wiper 203, brush 220, terminal 230,and thence aspreviously traced to ground at the contact of relay 252. The re-' lay257 operates in series with the generator 214. If the relay 254 operatesbefore the next silent interval, relay 257 is maintained by a circuitleading through the condenser in parallel with the inner right contactof relay 254. When the next silent interval oc curs, relay 257 releasesand from this point the circuits function as hereinbefore de scribed. Itwill be noted that if relay 217 has operated in series with relay 257,it is released by the operation of relay 254 to release in turn therelay 129 to prepare the circuit of relay 125 before current istransmitted from the source 261." i

On a call to a subscriber, a circuit is closed through the subscribersloop to operate re lay 216. Belay 216 connects ground to conductor-210,through the winding of relay 201, and thence to conductor 134, leftfront contact of relay 124, rightfront' contactof relay 115, outer rightback contact of relay 126,

inner right front contact of relay 116, windin of relay 129, outer rightback contact of re ay 127, to conductor 135, and thence to batterythrough relay 202. Relay 129 is thereby operated to close a circuit fromground on the left front contactsof relays 128 and 129 to batterythrough the winding of relay 123. The operation of relay 123 reversesthe circuit hereinbefore traced through relay 115 thereby supplyingbattery over conductor 117 instead of over conductor 118, causingmessage register 106 to operate and charge the call. a

As there isno charge made for a call to an intercepting operator, it isdesired to prevent message' register 106 from operating. This is done bymeans of slow-to-release relay 128 and alternating current relay 125.Relay 128 is made slow-to-release for the purpose of keeping the circuitfor relay 125 closed should false ringing current be trans mittedmomentarily over lead 134.

The operation of relay 125 was mentioned above and its operating circuitmay be traced from ground on theleft front contact of re lay 128,1eftback contact ofrelay129, windingof relay 125, innerle'ftback contact ofrelay 126, conductor 134, inner front contact of'relay 132, brush 140,terminal 210, com ductor 225, right back contact of relay 209,side-switch wiper 213, brush 221, terminal 231, outer left front contactofrelay 233, ring of jack 240 and plug 241 to ringing generator 261through the outer front contact of relay 253. The operation of relay 125opens the locking circuit of relay 128, thereby opening the above tracedcircuit for relay 123. It is therefore apparent that the measuredinterval of ringing current from the intercepting operators cord willprevent the operation of register 106.

,When a manual operator is" requested to obtain a connection with asubscriber in a three-wire oflice, plug 305 of the operators cordcircuit 0C (shown on Fig. 3) is inserted in jack 306. Relay 307 operatesover a circuit from ground through its winding, conductor 312, sleeve ofjack 306 and plug 305,

lamp 304, resistance 300, to battery. At the same time relay 311 isoperated over a circuit from-battery through its winding,back contact ofrelay 315, conductor 323, tip at of jack; 306 and plug305, upper normalcontact of key 303, upper winding of repeat coil 350 to ground. Relay309 also operates over a 307, -inner left fronticontact of relay 3 09 toground through its winding. Theoperation of relay 309 alsoconnectslrelay 313 to the ring sideof the 'trunltover conductor 322 and operatesrelay 310 overv a circuit from ground on the middle left front contactof relay 309 to battery through thewinding of relay310. Relay 313 doesnot operate at this time. To mark the trunk as busy, relay 309uponoperating connects the make-busy circuit329 throughthe coil 319 over theright front contact of relay 309 to the sleeve of jack 6. -The operation.of relay 310, (ionnects the windings of relay-315 in series withresistance 321 and coil 320 across conductors 324 and 325 but re1ay315does not operate at this time. ltsoperation will .be described later.The circuit is now in condition for dialing and the manual operatoroperates key 303, thereby connecting dial 302 across the tip and ring ofthe cord. Relay 311 re-' mains operated through contact '326 of'thedial. When the dial is moved ofli normal,

ground islconnected to the ringithroughoif- -normalcontactr327, lowermake contact of key' 303, ring of pl ug.305 and jack 306, conductor322-, outerleft front contact, of relay 309, right backcontact ofirelay314 tobat tery throughjthewinding: of relay313. The

operation of relay 313 connects conductor 351 to conductor 335 andoperates relay 317 over 7 an obvious circuit. Relay 31? operateddisconnects conductor 33; from conductor 324 and connects ground fromits left front. contact, over the front. contact of relay 311 throughthe winding ofrelay 316 to battery,

thereby operating relay316. .Rela .316 looks over a circuit from batterythroug its winding,,left front contact,-back contact of relay 318toground on the middleleft front contact of relay. 309. v v J While thedial 302'returns'tonormal, the

'pulsingcontacts 326 open and closetheoperating circuit for. relay 311 acertain number of times I corresponding, to the digit dialed. Theoperation and releaseof relay 311 intermittently connects ground toconductor .335

for operating the vertical relay, 330 inthe 'first trunk selector FT S'overacircuit from ground, on the left front contact of relay 317, backcontactofrelay 311;, outer right front contact of relay 313,. conductor.335to' battery through the winding of vertical relay mal,theolf-normatcontact.327'isopened .and relay 313, releases openingithecircuit 330. Theoperation will befthe same is described above for thefirstitrunk selectors with the exception of the rotary impulse from thetrunk OT. When the dial Ireachesnorthrough relay317 Relay 317, however,being slow to release, releases after an interval duringWhich timeground from the right inner back contact ofrelay 313 (which contact is amake-before5breakI spring combination) is connectedto conductor. 33f];causing relay 331 to operate and cause the trunk" selector to rotate ashereinbefore described.

'Itwill be notedthat thenumb'ering forv this particular circuit is thesame on both figures with the exception of the hundreds numeral whichcorresp ondsto the figure number. The connector C and interceptingoperators circuits will function in thesame manner as describedaboveuntil ringing source 261 is applied to the connection.

On acall successfully completed to a subscribers substation, when thesubscriber 320, resistance 321 and the right front contactof relay 310to conductor 324 and battery at relay 202.]..The operation of relay 1315opens the, circuit forrelay 311"releasing it,

andcloses a circuit for relay314: from ground removes the receiver. from'the switchhook, I

through the upper winding of repeat coil3'50,

upper normal contact of key 303, tip of plug 305 and jack306,;condu'ctor 323, fr0n't"contact of relay 315, rightv {front contactof relay 316, -winding of relay 31%1,;conductori3 22,

ring of jack 306 and plug 305, lower normal contact of key .303, windingof relay 308, lower winding of repeat'coil350 to battery.

The. resistanceof'relay 31 1 is such that it al-v lows relay 308. tooperate and connect resistance355across thelamp 30a extinguish ingiitfThe extinguishing' of lamp 304 indicates to the originating operator'tha't the connection has been {successfully completed and shemayfoperateljme ans to charge the n is 'therefore not dear ut"v tagaaaeoperator a'signal'on a'call to an intercepting operator. This iseffected by means of ringwinding of relay 318,1eft back contact ofdug-source 261 over a circu it1-from;ground on the middle leftfrontcontact of'relay 309,

relays 31a and 313, ,rightffront contact/of .rela-y 310,-conductor 324,right backc'onta'c t ofrelay317, conductor 33 1, inner left frontcontact'of relay332, brush 34:1, terminal 211, i M

r 20 9, siderswit'chwiper 213, brush 221;, 1 terminal 231, outer leftfrontcontact of relay .233, ring of'jack 24:0 and plug 24:1, to ringingsource'261 through the inner-right front 'conftactofrelay 253; Relay 318operates'fin this I circuit" and opens :the' locking circuit for, islow-to'-rel'ease relay 316, "This relayismade 1 3 slow to releaseinorder that it hold dun conductor 225, right "back 'conta'ct of relay ingshort impulses of ringing curreiitjwhich may occur at times otherthanrequir'ed. It; :is necessary for'relay' 318 to buzz aycertain I V 1length oftimein orderl't-o releaserelayf316. V

Ill-he release of relay 316 opens theoperating circuit for relay .314,and the circuit for loperatingsupervisory relay 3 08 is not therei tofore effective and. nosupervisory signal is received b the manualoperator.

When t e conversation is completed, the callingsubscriber replaces hisreceiver on the switchhook. The operator at position 00 takes down theconnection, releasing the relays 201 and 202. The connector C is nowrestored to normal. by means of a circuit from battery, through thewinding of release magnet 208, upper contacts of the combination 219,left normal contacts of the spring combination 218 to ground on theterminal 212. Magnet 208 causes the connector to restore to normal andrelay 333 operates to brin aboutthe release of the selector in thewellown manner. The withdrawal of the plug 305 from the jack 306releases relay 307, which in turn, releases relay 309. I The I'eleaseofrelay 309 opens the circuit of relay 310.

If the operator at QC desires to break down the connection after it hasbeen extended to the trunk IOT, but'before the operator at IOGhasanswered, she may doso by withdrawing the plug 305, whereupon relays307, 309 and 310 release. The release of relay 311) which is aslow-releasing relay, permits the connection of ground over twocircuits, one from battery, through the winding of relay 201, thenceover the circuit previously traced to the outer left front contact ofrelay 332, conductor 335,0uter right back contact of relay 313,conductor 325, left front contact of relay 310, lowerwinding of relay315,-to'ground at the middle left back contact of relay 309. Theothercircuit may be traced frombattery throughthe winding of relay 202,thence as traced to the inner left front contact of relay 332, conductor334, right back contact of relay 317;conductor 324, right front contactof relay 310, left back contact of relay 307, upper winding of relay315, to

groundat the middle left back. contact of relay 309. The operation ofrelays 201 and 202 closes a circuit from battery t rough the .Wiudin ofrelease magnet 208, upper contacts ol 'the spring combination 218, rightcontacts of thespring combination 219 to and 202 in a mannersimilar tothat described;

What is claimed is:

1. In a telephone exchange system comprising automatic switches employedfor extendin calls from one subscri er to another and on charging meansautomatically operable upon completion of such calls, interceptingoperator position circuits to which certain current to operate saidrelay calls are automatically extended, apparatus to disable theoperating circuit for said" call charging means, an interceptingoperators cord circuit, and means in said cord circuit automaticallyoperable to operate said disablin apparatus.

2. Tn a telephone exchange system comprising automatic switches employedfor ex tendin calls from one subscriber to another and ca 1 chargingmeans automatically operoperable upon completion of such calls, in-

tercepting operators position circuits to which certain calls areautomatically extended, an alternating current relay effective whenoperated fora measured length-10f time to disa le the operating circuitofsaid call charging means, an intercepting operators cord circuitrandmeansin said cor circuit toautomatically supply alternating current tooperate said relay forsaid measuredlength of time. i

4. In a telephone exchange system comprising automatic switches employedfor extending calls-from one subscriber to another and call chargingmeans. automatically operable upon completion of such calls,intercepting operators position circuits to which said calls areautomatically extended, an alternating current relay, means underthecontrol of saidrel'ay effective when said relay is operated forameasuredlength of time to disable the operatingcircuit of said call char'ng means,an interc ting operatorscor circuit, and means m'said cordcircuit to automatically supply alternating for-said measured lengthoftime.

5. In a telephone exchange system com prising automatic switches emloyed for extendin calls from one subscriberto another and ca l chargingmeans automatically operable upon completion of such calls, interceptingoperators position drcuitstowhichcertam calls are automaticall eratedfor a measured length of timeto disable the operating circuit for saidcall charging means, anintercepting operators cord circuit,meansin saidcircuit to automatically supply alternating currentto operate said relayfor-said measured len th of time, and means to render said disabfingmeans inefextended, an alternatingcurrent relay e active whenopfective'if said. alternating current relay is operated for less than saldmeasured length of time.

6. In a telephone system having aplural-, ity of lines, automaticswitches for extending connections from an originating point to a calledline, a current responsive device at the originating point,,meanscontrolled by the called party in answering for operating said device,an intercepting operators position I and a cord clrcuit thereat meansfor causing said switches to extend certain connections to saidposition, means in the op'erators cord circuit forsending adiscriminatory'signal back over the extended connection to theoriginating point, and means operated in re sponse to saidlsignal fordisabling the means for operating said current responsive device.

7. In a telephone system, a calling oflice and a called ofiice, trunklines interconnecting said offices,automati -switches for-eXQ operatingsaid current responsive device, 7 means for dlsabling sald currentrespons ve J tending connections from the calling oifice device, anintercepting operators position at the called office, means for causingsaid switches to route certain connectlons to-sald position, a cordcircuit at the operators position, and means in said cord circuit forcausing the operatlon of said dlsabllng means to prevent the operationof said current responslve ClGVlCGlIl the calhng office.

In Witness whereof; We hereunto subscribe our names, this 27th day ofAugust, A. D.,

'EMIL JACOBSEN. I ARTHUR B.- SPERRY,

